My friend has a male crowntail. But heres the problem. He is pale, lethargic, and dosent really move. He just sits down at the bottom of his tank. Hes in like a 3 or 4 gallon tank no filter or heater. I herd hes like this because of the heater because its to cold but they wont buy a heater so i dont know what to do. I change the water for him so il make it hotter. Is there anything else i can do to help it?

Better yet, a thermometer... you don't always need a heater. I don't have one yet in my tank, its 100+ outside in Vegas but our house is 78 degrees controlled climate. So between that and the hot air coming through my bedroom window I manage to keep it around 80.